Among the uses of local IP-based services provided by 3GPP LTE include direct communication between user equipments (UEs) in proximity (e.g., typically less than a few tens of meters, but sometimes up to a few hundred meters) of each other. Such device-to-device (D2D) communication provides advantages over communication between a UE and a radio access network (RAN), such as UE-eNB communication. Such advantages include capacity gain, peak rate gain, and latency gain. In addition, D2D communication allows UEs to sense their proximity to each other, which enables proximity-based services (ProSe) and applications.
D2D communication may involve many-to-many communication, in which each transmitting UE targets multiple receiving UEs (i.e., a broadcast to multiple UEs) positioned at different locations. Because propagation delays are different for each D2D link between two UEs, a transmitted D2D signal arrives at different UEs with different delays with respect to a synchronization reference signal. The different propagation delays may cause interference in D2D communication.